Mg add How many Days? You kiddin' me?

[dbowman5]

so: i made up a sample solution 1/4 cup Instant Ocean salts to 1/2 gallon RODI.(RODI TDS 10 ppm) tested it:
my solution --------------------- IO specs
refract. 1.025 ------------------- 1.022
API KH 8 dKH ----------------- 11dKH
Salifert Mg 975 ----------------- 1350
Hanna Ca 301 ----------------- 400
API Hi range pH 7.9----------- ?

i have added Magnesion to the tank
tested also
today --------------------------------------- 4/11/20 before Magnesion add
refract. 1.025 --------------------------- 1.025
API KH 6 + dKH-------------------------- 6
Salifert Mg 1155 ------------------------ 975
Hanna Ca 381 ------------------------- 321
API Hi range pH 8 -------------------- 8.1

my thoughts are thus: i don't trust the API test, both the reagents and my color sense. If I look at the fresh results vs the specs, I find a pretty consistent 72-75% of their specs. Except for the alkalinity the tank on 4/11 is similar to the fresh SW results. I think that I may ease the Alk up two points slowly. Starting when the ESV has dissolved.

 

[dbowman5]

just ordered: calibration solution for the refract., a pH pen, and a Salifert Alk/KH test kit. I'm gonna get to the bottom of this or be able to stand on all the stuff to get a good look at it. lol

 

[Randy Holmes-Farley Verified Community Expert]

I'd also suggest raising the salinity to 35 ppt as it will raise both calcium and magnesium.

 

[dbowman5]

I'd also suggest raising the salinity to 35 ppt as it will raise both calcium and magnesium.

thanks that looks like a plan.

 

[Randy Holmes-Farley Verified Community Expert]

Let us know how things turn out.

 

[dbowman5]

Let us know how things turn out.

certainly

 

[Reesj]

ITs not the test solutions but most probably the fault of your salt. If not most probably you might be doing a small mistake when doign the tests. (Like geting fluit all the way up to 1ml mark instead of below it)

 

[dbowman5]

ITs not the test solutions but most probably the fault of your salt. If not most probably you might be doing a small mistake when doign the tests. (Like geting fluit all the way up to 1ml mark instead of below it)

thank you, i have a growing zoa and a lot of coralline algae growth, crabs and a lot of shedding amphpods and hermits growing, but other than that no hard corals that would be consuming minerals. I am adding SW instead of RODI for evaporation to raise the salinity and salt components.

 

[dbowman5]

hi again. i wanted to give you an update. i bought calibration fluid for the refract. the reading was indeed off instead of 1.025 the tank was 1.023. i raised the concentration of the mix to 1.03 and have been using it for topping off. the sp. gr.
this evening is 1.026

 

[dbowman5]

happy May. as you have read I have been dding SW as top off. using 1.03 concentration to all three systems because all are low. My 75 has reached 1.026 so i will start using RODI; the 50 gal combined bow front and sump, and the fallow QT are still low so I will keep using SW on them. at 1.026 mt dKH is 9 the Ca is 379, and the Mg is 1080. the pH is 7.9, nitrates <5 ppm, temp 79 deg F. the water level in the sump is still a little high so i expect an incremental increase in concentrations over the next day, but your suggestions that the issue was low salinity were spot on. thank you reefers!